1. Field of the Invention
The present invention relates to a display device and a layout method for pixel circuits, and particularly to a panel type display device and a layout method for pixel circuits in the display device.
2. Description of the Related Art
In a field of display devices, panel type display devices such as liquid crystal display devices (LCDs; Liquid Crystal Displays), EL (Electro-Luminescence) display devices, plasma display devices (PDPs; Plasma Display Panels) and the like have recently been becoming mainstream in place of CRTs (Cathode-Ray Tubes) in related art, because the panel type display devices have features of small thickness, light weight, high definition, and the like.
In an active matrix type display device formed by disposing an active element in a pixel circuit including an electrooptic element among the panel type display devices, a circuit can be formed with a TFT (Thin Film Transistor), so that the functionality of the pixel circuit can be improved by the TFT circuit.
In the active matrix type display device using the TFT circuit, there are variations in TFT characteristics such as threshold voltage Vth, mobility μ, and the like, and therefore higher image quality is generally achieved by providing a correction circuit in each pixel circuit and correcting the variations in the TFT characteristics by the correction circuit. When a correction circuit is thus provided in a pixel circuit, the number of power supply lines for supplying power supply voltage to the pixel circuit tends to be increased. The increase in the number of lines squeezes the layout area of a pixel, thus preventing the achievement of higher definition with an increase in the number of pixels of a display device.
Thus, in related art, a power supply line is disposed between two pixel circuits adjacent to each other, and the power supply line is shared between the two pixel circuits, whereby the layout area of pixels (pixel circuits) is reduced, and higher definition of the display device is achieved (see Japanese Patent Laid-open No. 2005-108528, for example).